IEEE Std 2411:2021 pdf free download – IEEE Guide for Human Factors Engineering for the Validation of System Designs and Integrated SystemsOperations at Nuclear Facilities
4.1 General
The general principles described in 4.2 through 4.6 provide high-level guidance for validation activities.Theseprinciples are the basis for an objective, systematic approach to HFE validation.Clause 5 and Clause 6 providedetailed guidance for conducting HFE validations consistent with these general principles.
4.2 Reasonable confidence
The general purpose of a validation effort is to establish reasonable confidence that a system can be safelyoperated by personnel during all conditions under which it is expected to operate during its lifetime.Reasonableconfidence is the standard of proof applied when reaching formal validation judgments. Validation testingcannot prove a component or system is safe under all conditions, but it can provide a basis for reasonableconfidence. Successful validation gives formal grounds, as needed, to allow the system to proceed to the nextstage in development, implementation, or use.
4.3 Impartiality
Validation should be performed impartially to fairly evaluate the design with no predisposition towardfavorable or unfavorable outcomes.The validation team and participants in validation tests should haveindependence from the design team. Criteria should be established during test preparation and planning.Validation conclusions should be based on considering all criteria and results, both favorable and unfavorable,and factors that may have compromised the tests. The basis for the conclusions should be able to be scrutinizedby third party review.
4.4 Representativeness
Validation ofasystem depends on selecting test scenarios that provide asound basis for inferring how thesystemwill work in real-world operation. Although validation testing need not be exhaustive to be representative,aspects of the design important to safety should be tested under the full range of conditions anticipated duringactual use, including off-normal and emergency operational conditions. Similarly, participants in validationtests should be representative of the intended user population of operators and plant staff in all characteristicsconsidered to substantively affect performance.
Validations are typically conducted using a representation of the design (i.e., a testbed such as a simulator)rather than the actual system to be validated.The accuracy of this representation should be sufficient to supportthe objectives of the validation activity for which the testbed is to be used.Additionally, the testbed shouldbe representative of the design at its level of maturity at the time of the validation test. In general, validationtests should be carried out after the design has been successfully verified using HFE, technical, and functionalrequirements to ensure that the correct design is validated.The validation test objectives should guide the levelof fidelity needed between the testbed and the design, and should reflect which aspects of the design fidelityare of greater or lesser importance.
4.5 Standardization and consistency
The test methods and procedures should be well defined,so that they can be consistently applied andmaintained.This includes training of participants;training of test team members; participant briefings;instructions for conducting scenario test trials; performance measure administration;treatment of data;participant debriefings after the testing; and documentation of results and conclusions. Standardization andconsistency help to ensurc the integrity of the validation process and results.
4.6 Incremental approach
The risk of identifying design issues and their rework late in a project may be reduced by validating systemor component design elements as early as practical in the design process. For a specific project, the overallspan of validation activities and the number of stages to be used are determined by the project team.Althoughthis guide does not advocate a specific number or sequence of validation stages, the plan for each stage ofvalidation tests should state its particular scope and objectives.